


Seasons of Love and Warfare

by Libelli



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses, かぐや様は告らせたい | Kaguya-sama wa Kokurasetai | Kaguya-sama: Love Is War (Anime)
Genre: Crossover, Dimension Travel, Magic, Multi, Perfect Tea Time (Fire Emblem: Three Houses), Shenanigans, choir practice, tactics - Freeform, this is a meme, vassals doing vassal things
Language: English
Status: In-Progress
Published: 2020-12-01
Updated: 2020-12-01
Packaged: 2021-03-09 18:46:53
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 3,195
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27810964
Author URL: https://archiveofourown.org/users/Libelli/pseuds/Libelli
Summary: The students of Garreg Mach accidentally open a portal to another dimensions, and the students of Shuchiin Academy decide to see what the glowing portal is about.
Relationships: Shinomiya Kaguya/Shirogane Miyuki
Kudos: 4





	1. The Portal

Rhea did not see the flash of light directly, she caught it as light flooded her office and just as quickly melted away. Rhea put down the papers she had been reading, and pushed her chair back from her desk. 

_ What in the world… _

The door to her office flung open, and that was enough to give Rhea pause. 

“ _ Rhea _ !” 

“What is it, Seteth?” 

Seteth was still stopped in the doorway, trying to catch his breath. Rhea glanced over her shoulder out the window. Nothing seemed wrong, or at least disastrously wrong. 

“One of the lessons with the students has gone awry, did you see that flash of light?!” Seteth asked. 

“And you ran all the way here in that time?”

Seteth ignored her question. “It was a joint-lesson in reason taught by the three professors. All the students with interest in the subject, including Flayn, had been present. It seems one of the students,  _ who I will choose not to name _ , brought in a dark magic book from the restricted section of the library. With the help of all those skilled people, a spell was released.” 

“What kind of spell?” Rhea asked. 

Seteth’s shoulders slumped. “See for yourself.” 

Rhea approached her window, and surprised herself by gasping. In the center of one of the walkways leading out of the cathedral was a portal. It glowed a soft purple and was not all entirely terrifying. 

“Do you know what that thing can do?” Rhea asked. 

“No, and I don’t know if I want to.” Seteth said. “I have a bad feeling about this.” 

* * *

“Do you know where Fujiwara is?” Shirogane asked. 

“She hasn’t shown up yet?” Kaguya asked. “Didn’t she say she was going to be early today?” 

Shirogane shook his head. The student council room was silent except for Ishigami clicking the buttons on his game. 

Kaguya sighed as she pulled out her cellphone. “I can have the police looking for her within the hour,” 

“That sounds good, but shouldn’t we-”

There was a thump in one of the closets. The three members of the student council looked up at each other and then towards the closet. Purple light seeped out from under it. The door swung open and Fujiwara somersaulted out. She groaned in pain and then quickly sat up. 

“Hi, guys!” she chirped.

“Fujiwara, what is that?” Kaguya asked. 

“Oh, nothing, just what appears to be an interdimensional portal, I made some new friends over there. You should really come check it-”

“No. I think Kaguya is referring to...whatever it is you’re holding.” Shirogane said, coming out from behind his desk. 

“Oooooooh,” Fujiwara said. She looked down at the cross of gold, bone, and sword in her hand. “I dunno, some kind of sword. Must be important to those people over there. A lot of them were screaming when I took it. ‘Give us back our Sword of the Creator’! And a whole bunch of other nonsense.” 

Kaguya wished it was not kind of cute that she and the president broke out in a sweat at the same time. 

  
  



	2. Tactics Talk

**Summary for the Chapter:**

> Linhardt comes through the portal and meets Ishigami

**Notes for the Chapter:**

> Pretend that the intros happened and nobody killed each other.

The portal was a little much. 

It  _ glowed _ purple. 

It swirled, and echoed with the faint sounds of ringing swords and church bells. 

The council was lucky the principal was an idiot and they were the only ones that had access to the council room. 

“Ishigami, are you sure you don’t want to come?” Shirogane asked with his head poking out of the portal.

Ishigmai looked up from his game. “ _ Absolutely _ .”

“There’s cool stuff over here, almost like the games you play.” Shirogane offered. 

“Yeah right,” Ishigami turned his attention back to his game. “I’ll watch your guys’ backs, and make sure no one here finds out about this  _ thing _ .”

Shirogane shrugged. “Whatever you say.” He disappeared into the portal that the other council members had gone through. Ishigami breathed a sigh of relief. Then, Shirogane’s head reappeared. “By the way some of the other students want to come over here.”

“Wha-”

Before Ishigami could protest, one of the other students stumbled through the portal. 

“Oh my,” he said looking around the room with wide eyes. 

Ishigami paused his game. “And you are?”

“Linhardt,” the other student said, “The only person brave enough to cross over in the name of research.” 

Ishigami rolled his eyes. “Just don’t break anything.” 

Linhardt stood and walked behind the couch he rested his chin in the palm of his hand and watched Ishigami play. “What are you doing?” 

“Trying to defeat the enemy mage.”

“Which one is your light magic user?” 

“The one with yellow hair.”

“Use him against the mage.”

“Can’t. He’s too weak. He’ll get crushed.”

“Weird, you’d think light magic attacks would defend against dark magic.” 

Ishigami looked up. “How did you know that.”

Linhardt shrugged. “Everyone knows that. But if he’s too weak do a ranged attack to get out of the mage’s line of fire faster.” 

Ishigami moved his archer into position. “Hey that’s a pretty good idea.”

“Thank you, I did get an A on my last tactics exam.” Linhardt said. “Now what about that weird wyvern?” 

“You mean the dragon? Oh, I got it taken care of. They’re weak to arrows so I’ll just get my other archer and-”

The other archer shot the dragon down. 

Linhardt nodded. “ _ Fascinating _ ,”

Today’s Results: Ishigami and Lindhart win.

  
  



	3. Choir Practice

**Summary for the Chapter:**

> Shirogane wants to join choir.

The last notes of the choir hung in the air, and Shirogane was sure as the harmony echoed throughout the cathedral that the goddess could indeed hear it from her heaven. He stood to clap, but caught himself before he could disturb the peace. 

Some of the students rushed to go to their next class or training. Others lingered.

“Mr. President, I take it you enjoyed listening.” Dorothea said with a tip of her cap and a wink. 

_ Good luck with that _ . 

“It was incredible!” 

“Well then, you should join sometime!” Annette said. 

Shirogane blanched. “Oh no, I couldn’t possibly-”

“Have you ever heard Lorenz try to sing.” Dorothea said. “You cannot possibly be worse.”

“I never said I was-”

“Besides you don’t have to be good to be part of choir! That’s the point of it.” Annette said. “Beautiful voices like mine and Dorothea’s carry the weaker ones. Right, Dorothea?”

Dorothea offered a smile. “Yes. Exactly like you and me.” She cleared her throat. “Anyway, we have another practice tomorrow before the fourth bell. Come by, if you want.” 

Maybe he  _ could _ sing as beautifully in a choir. Or at least this  _ holy _ choir. 

Kaguya would sure be impressed. 

Shirogane smiled. “I’ll see you then.”

* * *

“So, then I said he was horrible! And do you want to know what he did?!” Annette asked. 

Dorothea picked at her nail. “He laughed?”

“He laughed! And asked me why I was shouting!” Annette cried. “I _ had every right to shout _ !”

“Oh, Annie, my dear, of course you did.” said Dorothea. “But maybe not now, practice is about to start, I don’t want you to strain your voice.”

Annette looked at the other students shuffling in and taking sheet music from the choir director. “Hey, do you think Shirogane is really coming?”

“Who knows,” said Dorothea, “That cutie might have busy president stuff to do. He’s like a house leader, but for like a whole school.” 

“That’s a shame,” said Annette, “I really wanted to hear him sing.” 

The doors of the cathedral burst open. The late afternoon sun illuminated a lone figure in the doorway. Cats scambered. Candles blew out, sending shadows across the cathedral. 

“I don’t know what you said or how you said it,” Fujiwara said stepping into the dim light, “But you are in for a world of hurt.”

“Fujiwara?” Dorothea asked. 

“I knew I should have warned you all about the president,” Fujiwara said as she strode down the aisle, “One school suffering his artistry is enough.”

Dorothea and Annette shared a look. 

Annette began. “I don’t-”

Fujiwara turned on her heel. “ _ You know exactly what you did _ .”

Annette debated breaking out a nosferatu. 

Fujiwara pinched the bridge of her nose. “Instead of playing with all your lovely cats, I’m now here. Duty calls.” She snatched the sheet music from the choir director and silenced her protests with a wave. “Oh no,” Fujiwara looked up. “You all are lucky to be in a place protected by your goddess. Don’t worry I’ll help to minimize the damage as much as I can.”

Before anyone could say anything, Shirogane walked into the cathedral. “Wow, why does everyone look scared? Is the song that hard?”

Today’s Results: Everyone loses. 

  
  



	4. Iino and Dimitri

**Summary for the Chapter:**

> Iino sees Dimitri (and his crest) train

The new school was way out of line. First of all, cats and dogs had the run of monastery grounds; their presence was inconsiderate of those with allergies, or those who could get easily distracted from studying. The fishing pond that the young professor frequented more often than her classroom was in no way sealed off. The cherry on top was that there was no dress code. 

Students and professors alike roamed the halls in various states of undress. Just the other day, Iino saw ‘Professor’ Manuela chatting away with a grappler from the Knights of Seiros, and it took all of her friends’ strength to carry Iino away from the scene and back towards the portal. 

Now, her friends were not here. 

_ I’ll be careful today _ , Iino thought,  _ I know Manuela hangs around that bridge over that chasm at this time, so I should be safe _ .

Iino looked down at her clipboard. So far, she had not talked to that awfully nice gatekeeper. Maybe today was the day to do it, he was bound to have something to report. 

As Iino turned the corner, she crashed into for all intents and purposes, what she thought was a wall. She landed hard on her backside, her papers flew in every direction.

“Oh my! Miss Iino, you have my deepest apologies!” 

Iino looked up to see the outstretched hand of Prince Dimitri. She took it and he yanked her to her feet. 

“Allow me to help you pick up what you dropped,” Dimitri said. He stooped down and gathered up Iino’s papers and then held them out to her. 

“Oh, thank you, what a gentleman,” Iino said, “There isn’t too many of those around here.”

“And there are those who parade around and pretend to be gentlemen.” 

“ _ Exactly _ !”

Dimitri smiled. “I hope you and your friends are enjoying your time here at the Monastery. I know I, and many others, have offered it before, but if you need help with anything, please do not hesitate to ask.”

_ This _ was the type of person Iino was looking for. 

“Where are you off to, your highness?” Iino asked. 

“The training grounds, I can show you to them, if you like.” Dimitri said. “And please, call me Dimitri. We are all students are we not?”

“That would be improper, your highness, but yes I would love to see the training grounds.” Iino said. “Do you keep up proper maintenance?”

They chatted about weapon safety on their way to the training grounds. The prince lamented over how some of the Golden Deer students were lax about weapons during their general tomfoolery, and Iino scribbled down some notes to give to some of those awfully dressed professors. 

Inside the training grounds the prince had various members of other houses waiting for him. 

“Don’t mind me, I’m just going to make sure all the knives are put away according to monastery code!” Iino said.

“ _ There’s a code _ ?” Caspar whispered. 

Iino began to assess the racks of weapons. Behind her, the students of the training ground started their exercises. 

“Let’s begin!” the prince declared. 

“Your highness, you can’t be serious.”

“Of course I am! This is good training for me!”

“You will never have to take on like ten people at once.” 

“Who knows?”

“Alright, you asked for it, boar.” 

Iino turned as she heard the ring of steel. There was the prince, taking on almost every single one of the students of his house. He blocked every blow. He countered every strike. He smiled as he knocked people over, relishing in the lack of challenge. 

_ Oh _ . Iino hugged her clipboard tight.

Then Felix charged the prince in a sneak attack from the back. Dimitri turned, disarmed Felix with a quick move from his spear and when Felix pulled a knife to attack again, the prince caught his arm. 

“Nothing you can do to stop me.” the prince said. 

_ So strong! _ Iino thought. Then other thoughts like dark clouds crept into the edges of her mind. _ I wonder what that strength could do to- _

Iino felt heat rise in her cheeks. 

“Miss Iino! What’s wrong with you?!” the prince called out. 

Iino barely contained her cry as she collapsed to the floor of the training grounds. 

When Iino came to, it was in the infirmary with Professor Manuela leaning directly over her. 

Today’s Results: Iino very much loses. 

  
  



	5. Presidential Teatime

**Summary for the Chapter:**

> Byleth invites Shirogane for tea- with less than ideal consequences.

“I think I should invite that new president to tea.” Byleth said as she looked over her journal. It would be a free day tomorrow.

“ _ Why _ ?” Sothis asked from her corner.

“I meet regularly with all the house leaders. He’s like one, just a little different.” Byleth said with a shrug. 

“Alright, be careful.”

Byleth turned. “Careful? The only weapons he’s ever picked up are probably in his daydreams.” 

“Having tea,  _ alone _ , that might insinuate-”

“Then I’m in a relationship with half the Monastery.”

“Rude! You didn’t let me finish!” Sothis huffed. “ _ Anyway _ , as I was saying, yes, sometimes it does look a little flirtatious to have tea with someone. However, I’m not worried about your reputation, but your very life.” 

“My life?” Now Byleth was interested. 

“Yes. It appears that the young Shirogane has an admirer of the deepest and truest kind.” 

“And?” Byleth asked. “Who is it? What’s she going to do?”

“It is his vice president, and I’m almost sure she would make an attempt on your life if she thought you were trying to seduce her president.”

“Kaguya? But she’s not in love with him?”

Sothis gave Byleth a look. “If I did not live in your head, I would not be able to believe you are this dense.” she sighed. “But of course you would not be able to see something like this.” 

“Dense? What do you mean-” 

“Never mind. The hour is late. You should sleep.”

* * *

The next day went as much as Byleth could have expected. She strolled through the market, got greenhouse dirt under her nails, and on her way to back from the library she ran into the president from the other school, along with his vice president. 

“Professor! Do you need help with your books?” Shirogane asked. 

“No, thank you.” Byleth said, “However, would you like to meet me for tea this afternoon, and tell me all about your school?”

Shirogane beamed and Kaguya’s face darkened. 

“I’d love to!” Shirogane said. “See you then!” 

He waved goodbye to Byleth and Kaguya, and went into the opposite direction. Kaguya fell into step besides Byleth. 

Kaguya reached for some of the heavier books out of Byleth’s arms. “Please, allow me to help you out.” Before Byleth could tell her ‘no’, the books were gone. They walked in silence.

“Tell me, Professor, does the Archbishop know you talk to yourself?”

“It’s cute, really! It’s almost as if you have an imaginary friend that can actually answer you!” Kaguya continued with a laugh. “And from what I hear it’s like she chastises you often.”

“The Archbishop doesn’t know, and I would prefer her to not to.” Byleth stated.

“Really?”

“This is  _ private _ .”

“I’ve been reading that negative self-talk, even from an imaginary friend is bad for you. If you can’t bring it up to the Archbishop, whom I’m sure would  _ love _ to help you, maybe I could. Since you are so busy this afternoon, maybe I can stop by her office for you, and tell her about your friend. What’s her name? It starts with an ‘s’?” Byleth stopped and Kaguya turned to face her, beaming. “Of course, if you were free this afternoon, I’d say you should go talk to her yourself without me interfering.”

Byleth glared at Kaguya, and for a moment she saw her glare back. She approached Kaguya and took her books back.

Later that afternoon, Shirogane was informed that emergency actions were required of the Knights of Seiros, and Byleth was the first to volunteer to leave the monastery.

Today’s Results: Kaguya wins. 

  
  



	6. Vassals in Every World

**Summary for the Chapter:**

> Hayasaka hangs with Dedue

Hayasaka supposed she had to go through the portal. After all, if Lady Kaguya was going to be spending time there she might as well prepare herself with any of the oddities that would surely follow her lady home. 

Hayasaka wandered around the monastery. The classrooms were classrooms. The greenhouse was a greenhouse. The dining hall had good food. Typical school. Just some flying horses. 

Hayasaka was about to leave when she came upon a large metal door cracked open. She heard the ring of steel and a woman shouting commands like a sports coach. 

Hayasaka opened the door. No one paid her a second glance. 

The professor named Byleth gave an order to her students, the group of them performed a move with their lances. The professor gave a nod. 

“Alright, group two take a break. Group one, get ready to do it again.” Byleth said. 

Three of the students, Ingrid, Felix, and Dedue, walked to the side of the training grounds. The professor was left with the one named Sylvain and the prince. 

The professor acknowledged Hayasaka with a nod and continued to teach. 

“Are you one of the  _ other _ students?” Dedue asked. 

“Yes.” 

Together they stood there watching as the professor taught the two students in front of her. 

“A real prince, huh?” said Hayasaka. 

“Yes, I have been with him for years.” Dedue said. 

The professor shook her head at Prince Dimitri and discussed the best way to use the lance move. The prince failed to grasp what his professor meant and Byleth scowled. 

“Here, let me help you.” Byleth said. 

_ This should be good _ . Hayasaka thought.

The professor grabbed hold of the prince’s arm and began to play out the motion she had wanted him to go in. The prince’s face turned bright red, but the professor seemed oblivious. She guided Dimitri’s arm; her fingers ran over his forearm and wrist, pointing out what he should have been doing, but running over them nonetheless. 

Prince Dimitri ripped himself out of his professor’s grasp. “T-thank you, professor! I believe I have it handled from here.” 

Byleth raised one eyebrow on her otherwise expressionless face. “ _ Prove it _ .” 

Hayasaka saw the prince’s brain short-circuit. She turned to Dedue. “So, you have one, too?”

“ _ I beg your pardon _ ,” Hayasaka only gestured to the scene in front of her. “Oh,” Dedue said. “You’re talking about your lady and the young man “It appears so.”

As they watched the prince flail miserably and the professor watched on, not understanding how he was so flustered, the forgotten Sylvain stepped forward. 

“Hey, professor, I could use more help, too...” 

Today’s Results: Hayasaka and Dedue win. 

  
  



End file.
